Axis: The longitudinal centre-line of the reamer
Back Taper: The reduction in diameter per inch length of reamer from the entering end towards the shank
Bevel Lead: The angular cutting portion at the entering end to facilitate the entry of the reamer into the hole.
Body: That portion of the reamer extending from the entering end of the reamer to the commencement of the shank
Circular Land: The cylindrically ground surface adjacent to the cutting edge, on the leading edge of the land
Cutting Edge: The edge formed by the intersection of the face and the circular land or the surface left by the provision of primary clearance
Cutting Edge Length: The axial length of that portion of the fluted body provided with primary clearances or circular lands and including the taper and bevel leads
Diameter: The maximum cutting diameter of the reamer at the entering end (also see Taper Reamer)
Face: That portion of the flute surface adjacent to the cutting edge on which the chip impinges as it is cut from the work
Flutes: The grooves in the body of the drill which provides lips and permit the removal of chips and allow cutting fluid to reach the lips
Heel: The edge formed by the intersection of the surface left by the provision of secondary clearance and the flute
Land: That portion of the fluted body not cut away by the flutes; the surface or the surfaces included between the cutting edge and the heel
Overall Length: The length over the extreme ends of the reamer
Primary Clearance: That portion of the land removed to provide clearance immediately behind the cutting edge
Recess: That portion of the body which is reduced in diameter below the cutting edges, pilot or guide diameters
Recess Length: The length of that portion of the body which is reduced in diameter below the cutting edges, pilot or guide diameters
Rotation of Cutting:
(i) Right hand cutting reamer. A reamer which rotates in a counter-clockwise direction when viewed on the entering end of the reamer.
(ii) Left hand cutting reamer. A reamer which rotates in a clockwise direction when viewed on the entering end of the reamer
Secondary Clearance: That portion of the land removed to provide clearance behind the primary clearance or circular land
Shank: That portion of the reamer by which it is held and driven
(i) Straight or parallel shank for machine use. A cylindrically ground shank without square
(ii) Parallel hand shank. A cylindrical ground shank provided with a square at its extreme for driving the reamer
(iii) Taper shank. A shank of recognised standard taper for machine use
Size of Square: The dimension across the flats of the squared portion at the extreme end of a parallel hand shank
Secondary Clearance: That portion of the land removed to provide clearance behind the primary clearance or circular land
Shell Reamers:
(i) Driving slot width. The width of the slot in the rear end of the reamer
(ii) Driving slot depth. The overall depth of the slot measured from the rear end of the reamer to the root of the radiused slot
Taper Lead Length: The length measured axially of the taper lead
Taper Reamers:
(i) Large end diameter. The maximum diameter over the tapered cutting edges
(ii) Small end diameter. The minimum diameter over the tapered cutting edges
NOTE: A taper hole is defined for size by stating the large end diameter and the taper per foot on diameter or the included angle of the taper, or as a taper ratio eg. 1 in 48(included)
The Tap and Die Company website has a lot of other very useful 'Technical’ Data & Information for you to view